using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
namespace SQL
{
  public static class SqlHelper
  {
    /// <summary>
    /// 创建连接的字符串
    /// </summary>
    static readonly string connStr=ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

 #region 1.0 执行查询语句，返回一个表 + static DataTable ExcuteTable(string sql, params SqlParameter[] ps)
    /// <summary>
    /// 1.0 执行查询语句，返回一个表
    /// </summary>
    /// <param name="sql">sql语句</param>
    /// <param name="ps">参数数组</param>
    /// <returns>返回一张表</returns>
    public static DataTable ExcuteTable(string sql, params SqlParameter[] ps)
    {
      SqlDataAdapter da = new SqlDataAdapter(sql, connStr);
      da.SelectCommand.Parameters.AddRange(ps);
      DataTable dt = new DataTable();
      da.Fill(dt);
      return dt;
    } 
    #endregion

    #region 2.0 执行增删改的方法 + static int ExcuteNoQuery(string sql, params SqlParameter[] ps)
    /// <summary>
    /// 2.0 执行增删改的方法
    /// </summary>
    /// <param name="sql">sql语句</param>
    /// <param name="ps">参数数组</param>
    /// <returns>返回一条记录</returns>
    public static int ExcuteNoQuery(string sql, params SqlParameter[] ps)
    {
      using (SqlConnection conn = new SqlConnection(connStr))
      {
        conn.Open();
        SqlCommand command = new SqlCommand(sql, conn);
        command.Parameters.AddRange(ps);
        return command.ExecuteNonQuery();
      }
    } 
    #endregion

    #region 3.0 执行存储过程的方法 + static int ExcuteProc(string procName, params SqlParameter[] ps)
    /// <summary>
    /// 3.0 执行存储过程的方法
    /// </summary>
    /// <param name="procName">存储过程名</param>
    /// <param name="ps">参数数组</param>
    /// <returns></returns>
    public static int ExcuteProc(string procName, params SqlParameter[] ps)
    {
      using (SqlConnection conn = new SqlConnection(connStr))
      {
        conn.Open();
        SqlCommand command = new SqlCommand(procName, conn);
        command.CommandType = CommandType.StoredProcedure;
        command.Parameters.AddRange(ps);
        return command.ExecuteNonQuery();
      }
    } 
    #endregion

    #region 4.0 查询结果集，返回的是首行首列 + static int ExecScalar(string sql, params SqlParameter[] ps)
    /// <summary>
    /// 4.0 查询结果集，返回的是首行首列
    /// </summary>
    /// <param name="sql">sql语句</param>
    /// <param name="ps">参数数组</param>
    /// <returns></returns>
    public static object ExecScalar(string sql, params SqlParameter[] ps) //调用的时候才判断是什么类型
    {
      using (SqlConnection conn = new SqlConnection(connStr))
      {
        conn.Open();
        SqlCommand command = new SqlCommand(sql, conn);
        command.Parameters.AddRange(ps);
        return command.ExecuteScalar();
      }
    } 
    #endregion
  }
}